RE: Schumacher's Newest Rc - Manic
Those bevel gears dont wear out too fast if you have them properly meshed right. Mines lasted a good while in my kyosho st-rr that was powered by a high performance .28. If you have a good quality kit, then parts wont wear like they do on rtrs or cheaper quality rc's. Your GTX2 is a truck with 2 BBs so u can expect transmission parts to go out like they do because its too much power for it.
But if belt drive is what you prefere offroad and your having good luck with it, no need to change then.